Cladosporium fulvum circumvents the second functional resistance gene homologue at the Cf-4 locus (Hcr9-4E ) by secretion of a stable avr4E isoform

Abstract Powdery mildew of barley, caused by Erysiphe graminis f. sp. hordei, is a model system for investigating the mechanism of gene-for-gene interaction between large-genome cereals and obligate-fungal pathogens. A large number of loci that confer resistance to this disease are located on the short arm of chromosome 5(1H). The Mla resistance-gene cluster is positioned near the telomeric end of this chromosome arm. AFLP-, RAPD-, and RFLP-derived markers were used to saturate the Mla region in a high-resolution recombinant population segregating for the (Mla6 + Mla14) and (Mla13 + Ml-Ru3) resistance specificities. These tightly linked genetic markers were used to identify and develop a physical contig of YAC and BAC clones spanning the Mla cluster. Three distinct NBS-LRR resistance-gene homologue (RGH) families were revealed via computational analysis of low-pass and BAC-end sequence data derived from Mla-spanning clones. Genetic and physical mapping delimited the Mla-associated, NBS-LRR gene families to a 240-kb interval. Recombination within the RGH families was at least 10-fold less frequent than between markers directly adjacent to the Mla cluster.

Download Full-text

Mapping and candidate gene screening of Cladosporium fulvum resistance gene Cf‐12 in tomato ( Solanum lycopersicum ) by high‐throughput sequencing

Plant Breeding ◽

10.1111/pbr.12852 ◽

2020 ◽

Vol 139 (5) ◽

pp. 977-987

Author(s):

Xinfeng Chai ◽

Xiangyang XU ◽

Dong Wang ◽

Dongqi Xue ◽

Jingfu Li

Keyword(s):

Candidate Gene ◽

Solanum Lycopersicum ◽

Resistance Gene ◽

High Throughput ◽

High Throughput Sequencing ◽

Cladosporium Fulvum ◽

Gene Screening

Download Full-text

Apple Contains Receptor-like Genes Homologous to the Cladosporium fulvum Resistance Gene Family of Tomato with a Cluster of Genes Cosegregating with Vf Apple Scab Resistance

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2001.14.4.508 ◽

2001 ◽

Vol 14 (4) ◽

pp. 508-515 ◽

Cited By ~ 111

Author(s):

Boris A. Vinatzer ◽

Andrea Patocchi ◽

Luca Gianfranceschi ◽

Stefano Tartarini ◽

Hong-Bin Zhang ◽

...

Keyword(s):

Gene Family ◽

Resistance Gene ◽

Resistance Genes ◽

Transmembrane Domain ◽

Venturia Inaequalis ◽

Scab Resistance ◽

Common Disease ◽

Resistance Locus ◽

Cladosporium Fulvum ◽

High Quality

Scab caused by the fungal pathogen Venturia inaequalis is the most common disease of cultivated apple (Malus × domestica Borkh.). Monogenic resistance against scab is found in some small-fruited wild Malus species and has been used in apple breeding for scab resistance. Vf resistance of Malus floribunda 821 is the most widely used scab resistance source. Because breeding a high-quality cultivar in perennial fruit trees takes dozens of years, cloning disease resistance genes and using them in the transformation of high-quality apple varieties would be advantageous. We report the identification of a cluster of receptor-like genes with homology to the Cladosporium fulvum (Cf) resistance gene family of tomato on bacterial artificial chromosome clones derived from the Vf scab resistance locus. Three members of the cluster were sequenced completely. Similar to the Cf gene family of tomato, the deduced amino acid sequences coded by these genes contain an extracellular leucine-rich repeat domain and a transmembrane domain. The transcription of three members of the cluster was determined by reverse transcription-polymerase chain reaction to be constitutive, and the transcription and translation start of one member was verified by 5′ rapid amplification of cDNA ends. We discuss the parallels between Cf resistance of tomato and Vf resistance of apple and the possibility that one of the members of the gene cluster is the Vf gene. Cf homologs from other regions of the apple genome also were identified and are likely to present other scab resistance genes.

Download Full-text

Additional Resistance Gene(s) Against Cladosporium fulvum Present on the Cf-9 Introgression Segment Are Associated with Strong PR Protein Accumulation

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.1998.11.4.301 ◽

1998 ◽

Vol 11 (4) ◽

pp. 301-308 ◽

Cited By ~ 38

Author(s):

Richard Laugé ◽

Alexander P. Dmitriev ◽

Matthieu H. A. J. Joosten ◽

Pierre J. G. M. De Wit

Keyword(s):

Resistance Gene ◽

Avirulence Gene ◽

Fungal Mycelium ◽

Protein Accumulation ◽

Cladosporium Fulvum ◽

Leaf Chlorosis ◽

Tomato Pathogen ◽

Or Genes ◽

Introgression Segment ◽

Weak Resistance

The existence of a gene or genes conferring weak resistance against the fungal tomato pathogen Cladosporium fulvum, in addition to the Cf-9 resistance gene, present on the Lycopersicon pimpinellifolium Cf-9 segment introgressed into L. esculentum, was demonstrated with strains of C. fulvum lacking a functional Avr9 avirulence gene and tomato genotypes lacking a functional Cf-9 gene, respectively. Two mutant strains, obtained by disruption of Avr9 in race 4 and race 5 of C. fulvum, do not trigger the hypersensitive response-mediated resistance on MM-Cf9 genotypes that is normally induced after recognition of the AVR9 elicitor. However, when these strains are inoculated onto MM-Cf0 and MM-Cf9 genotypes, adult MM-Cf9 plants still show weak resistance. This resistance is not related to the Cf-9 gene, as ethyl methanesulfonate (EMS)-generated Cf-9 mutants retained weak resistance. Growth of the fungus in the leaf mesophyll is strongly inhibited, whereas re-emergence of fungal mycelium and conidiation are poor. Strong accumulation of pathogenesis-related proteins and early leaf chlorosis are associated with this phenotype of weak resistance. A search among natural strains lacking the Avr9 gene revealed that one strain is able to overcome this weak resistance. Possible mechanisms underlying this weak resistance are discussed. The presence of the additional weak resistance gene(s) could explain why the resistance of Cf9 genotypes has not been overcome so far in practice.

Download Full-text

Assignment of Amino Acid Residues of the AVR9 Peptide of Cladosporium fulvum That Determine Elicitor Activity

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.1997.10.7.821 ◽

1997 ◽

Vol 10 (7) ◽

pp. 821-829 ◽

Cited By ~ 43

Author(s):

Miriam Kooman-Gersmann ◽

Ralph Vogelsang ◽

Erwin C. M. Hoogendijk ◽

Pierre J. G. M. De Wit

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Resistance Gene ◽

Expression System ◽

Potato Virus X ◽

Cladosporium Fulvum ◽

Amino Acid Residues ◽

Tomato Plants ◽

Loop Region ◽

Relationship Of

The AVR9 peptide of Cladosporium fulvum is an elicitor of the hypersensitive response in tomato plants carrying the Cf-9 resistance gene (MM-Cf9). To determine the structure-activity relationship of the AVR9 peptide, amino acids important for AVR9 elicitor activity were identified by independently substituting each amino acid of AVR9 by alanine. In addition, surface-exposed amino acid residues of AVR9 were substituted by other amino acids. Activity of the mutant Avr9 constructs was studied by expressing the constructs in MM-Cf9 tomato plants, using the potato virus X (PVX) expression system and assessing the severity of necrosis induced by each PVX∷Avr9 construct. This allowed direct identification of amino acid residues of AVR9 that are essential for elicitor activity. We identified amino acid substitutions that resulted in AVR9 mutants with higher, similar, or lower elicitor activity compared to the wild-type AVR9 peptide. Some mutants had completely lost elicitor activity. A selection of peptides, representing different categories, was isolated and injected into leaves of MM-Cf9 plants. The necrosis-inducing activity of the isolated peptides correlated well with the necrosis induced by the corresponding PVX∷Avr9 derivatives. Based on the necrosis-inducing activity of the mutant AVR9 peptides and the global structure of AVR9, we assigned sites in AVR9 that are important for its necrosis-inducing activity. We postulate that the “hydrophobic β-loop” region of the AVR9 peptide is crucial for necrosis-inducing activity in tomato plants that carry the Cf-9 resistance gene.

Download Full-text

LINKAGE RELATION OF RESISTANCE TO CLADOSPORIUM LEAF MOLD (Cf-2) AND ROOT-KNOT NEMATODES (Mi) IN TOMATO AND A NEW GENE FOR LEAF MOLD RESISTANCE (Cf-11)

Canadian Journal of Genetics and Cytology ◽

10.1139/g80-023 ◽

1980 ◽

Vol 22 (2) ◽

pp. 183-186 ◽

Cited By ~ 6

Author(s):

E. A. Kerr ◽

Elizabeth Kerr ◽

Z. A. Patrick ◽

J. W. Potter

Keyword(s):

Lycopersicon Esculentum ◽

Resistance Gene ◽

High Resistance ◽

Chromosome 6 ◽

Cladosporium Fulvum ◽

Linkage Relation ◽

Leaf Mold ◽

New Gene ◽

Indian River ◽

Mold Resistance

Mi derived from Anahu and Cf-2 derived from Indian River are approximately at locations 35 and 43 on the long arm of chromosome 6 of the tomato (Lycopersicon esculentum Mill.). Ontario 7716 contains the leaf mold resistance gene Cf-11 which was derived from an aberrant plant of Mass. #2. Both Cf-2 and Cf-11 confer immunity from Cladosporium fulvum Cke. races 1 and 10. Cf-11 confers high resistance to race 6 and slight tolerance to race 12 whereas Cf-2 does not confer any resistance to these races of C. fulvum.

Download Full-text